Spinal fixation constructs are utilized to provide stability to the spine. Most often the fixation construct is used as an adjunct to fusion surgery during which adjacent vertebrae are prepared to facilitate bone growth between them. Because motion between the vertebrae tends to inhibit bone growth, the fixation constructs are employed to prevent motion so that bone can grow and achieve a solid fusion. When the position of one or more vertebrae must be adjusted to restore a more natural alignment of the spinal column, the fixation construct also serves to maintain the new alignment until fusion is achieved.
Fixation constructs of various forms are known in the art, of which, rod based fixation constructs are one of the most common. Typically in a rod based construct multiple anchors are coupled to a portion (e.g. the posterior elements) of two or more vertebrae and then connected by a fixation rod. The anchors further include a rod housing in which the fixation rod is captured and locked. The rod housing may be fixed or rotatably coupled to the anchor portion and generally includes a pair of upstanding arms separated by a rod channel. When constructing the fixation construct the surgeon must align and seat the rod in the rod channel of each anchor, an undertaking that is generally referred to as “reduction”. Reduction can be a challenge, particularly when one or more of the vertebrae to be connected are out of alignment with other vertebrae, and the reduction distance and force requirements can vary greatly from anchor to anchor. Known rod reduction instruments or reducers, can be bulky, time consuming or frustrating to employ, limited in achievable reduction depth, and other issues that can make them less than desirable. The various rod reduction and other instruments described herein are directed towards facilitating simple and efficient rod and/or screw manipulation during installation of a fixation construct.